Evan Freiburg(NEW YORK) -- A survivor of a rare form of cancer, who had part of his leg amputated as well as undergone radiotherapy, chemotherapy and multiple surgeries, did not let any of those factors stop him from leading a team of bikers this weekend at an event to raise funds for rare cancer research.

Freiberg, who is a radiologist, was diagnosed with leiomyosarcoma, a rare cancer, in February 2016. Shortly after, he had his left leg amputated below the knee, and initially things were looking optimistic.

During a routine CT scan in October 2016, however, doctors said that his cancer had spread to his lungs. Following radiotherapy, chemotherapy and surgery, Freiberg celebrated being cancer-free in July 2017.

But by October 2017 he learned that the cancer had spread to his spine. Despite his harrowing, ongoing, health battle, Freiberg continues to remain optimistic and still works full-time.

This weekend he spearheaded a team of bikers at the Memorial Sloan Kettering Cancer Center's Cycle for Survival in New York City, which raises funds for cancer research through indoor cycling events. Cycle for Survival has raised $165 million for cancer research since 2007, according to its website.

"The great thing about Cycle for Survival is I have a lot of family members who want to help us but its not like they could go into the laboratory and discover a cure for sarcoma, but this is a way for them to help," Freiberg said.

Almost 13 percent of all cancers diagnosed in patients 20 years old and above in the U.S. are defined as rare cancers, according to a 2017 report from the American Cancer Society.

"Any cancer diagnosis is difficult, but rare cancers can be especially challenging for patients," the report stated. "After diagnosis, patients and caregivers often have a hard time finding information about their cancer, and treatment options are usually more limited and less effective than for more common cancers."

'There is nothing to do but feel hope'

Felicia Freiberg, Evan's wife, said that when she first found out about her husband's diagnosis, "the first thing that went through my mind was our kids."

"These statistics were terrible, and I was terrified about what was going to happen to our family and if we lost Evan," she said. "How it would affect our children? How I was going to raise them without my husband?"

She said that they found "hope" when they went to Memorial Sloane Kettering Cancer Center and met with the doctors there.

"There is nothing to do but to feel hope," she said, adding that her husband is her main source of inspiration. "He never slowed down for a second, he never seemed defeated for a second.

"When he heard that he had to have the amputation ... he made a joke at the time, he was trying to add levity to the situation," she added.

Felicia Freiberg biked alongside her husband at this weekend's event.

"I feel like he’s an incredible warrior and if he can have this motivation and attitude, the least I could do is try to be a support to him, and try to have the best attitude and outlook that I can," she said.

She also thanked all those who supported their family's journey, and donated to their Cycle for Survival team.

"People may not realize that giving just a little bit of money is so important to people facing a rare cancer or people battling for their lives," she said. "And it really is, because it goes toward research which can help save your loved one's life."